Texture Disappeared in Cycles Render
Blender Internal and Cycles are two different render engines, each of them has it's own materials and shaders.Objects that have BI materials will not render correctly in another render engine, that includes Cycles, so you need to reassign Cycles materials to your objects.
Your objects unwrap has nothing to do with what render engine you are using, so the good news is that you don't need to unwrap again.